322 MARKETABLE BRITISH MARINE FISHES 



the Irish Survey only sand-eels and herrings were recognised. In 

 the aquarium at Plymouth, I have noticed that the dory has a 

 peculiar and interesting method of securing its prey. It does 

 not overtake it by superior speed like the mackerel, or lie in 

 wait for it like the angler, but stalks it and approaches it by 

 stealth. It is able to do this in consequence of the extreme 

 thinness of its body, and the peculiar movement of its hinder 

 dorsal and ventral fins. The dory places itself end on towards 

 the fish it desires to devour, and in this position it is evident that 

 it excites no alarm on the part of its pre)-. The appearance of 

 the dory seen in this way is a mere line in the water, to which 

 no particular significance can be attached. I have not particu- 

 larly noticed the effect of the ribbons of membrane, which project 

 from the dorsal fin. But I have observed that the movements of 

 the dory are very gradual, except in turning : it alters the 

 position of its body by a turn of the tail or side fins, and then 

 slowly swims forward b}^ vibrating the second dorsal and ventral, 

 a movement which causes very slight disturbance of the water. 

 The whole appearance of the dorj- in these actions is suggestive 

 of suppressed excitement, his e\'es being fixed on his prey. I do 

 not recollect seeing him actually swallow another fish, but have 

 no doubt that he gets near enough to a sprat for example, with- 

 out alarming it, to seize it by the sudden elongation of his 

 curious jaws. 



Breeding. — In the Irish Survey ripe females were found in July 

 and August, and one spent in June. At Plymouth I found them 

 ripe in August. This is enough evidence to indicate the spawning 

 season, but unfortunately no one has examined the eggs. In all 

 probability they are of the same type as those of the boar-fish 

 above described. The larvae and their transformation also are 

 at present unknown, but considerable evidence has been collected 

 concerning the growth of the young. In summer, from June to 

 September, specimens from a little less than 5 inches to 7-3 inches 

 in length are taken in considerable numbers by the trawlers at 

 Plymouth, at depths from 5 fathoms to 35 fathoms. It is clear 

 that these cannot be less than a year old, and there is no reason 

 to suppose that they are more. Smaller specimens are taken in 

 autumn and winter. The only one I have recorded was 17 inch, 

 taken in Cawsand Bay, Plymouth Sound, at the beginning of 

 October. This one I consider to have been about three months old. 



